With the development of input and display technologies, a combination of a display device and a touch-control device has become a trend which meets market requirements. In conventional technologies, a display device may have the touch-control function by the following methods. Conventional touch-control devices may be classified into three types: resistive, capacitive and electromagnetic. A resistive or capacitive handwriting input device receives an input signal by identifying a touch event. Generally, a resistive or capacitive handwriting input panel is disposed as an independent part on an external side of a liquid crystal displayer to face a user to receive a touch event. An inductive handwriting panel identifies an input position by receiving an electromagnetic signal of an electromagnetic pen and is generally disposed as an independent part on an external side or the back of a liquid crystal display device, such as the back of a backlight module.
In the above method which realizes a handwriting input function of a liquid crystal display device, a handwriting input panel as an independent part may increase a thickness of a liquid crystal display device, which goes against the development trend in liquid crystal display device of being thin and light-weight. Besides, the installation of a handwriting input panel and a liquid crystal display device may lack of stability and fastness, thereby reducing the input accuracy.